package com.example.socket.thread;

import java.util.Date;
import java.util.concurrent.Delayed;
import java.util.concurrent.TimeUnit;

/**
 * @author
 * 延时元素对象
 */
public class DelayedElement<T> implements Delayed {

    /** 元素内容 */
    private T content;
    /** 过期时间 */
    private Date end;

    public static <T> DelayedElement<T> valueOf(T content, Date end) {
        return new DelayedElement<T>(content, end);
    }

    public DelayedElement(T content, Date end) {
        this.content = content;
        this.end = end;
    }

    public T getContent() {
        return content;
    }

    public Date getEnd() {
        return end;
    }

    public void setContent(T content) {
        this.content = content;
    }

    public void setEnd(Date end) {
        this.end = end;
    }

    @Override
    public long getDelay(TimeUnit timeUnit) {
        long now = System.currentTimeMillis();
        long delay = end.getTime() - now;
        switch (timeUnit) {
            case MILLISECONDS:
                return delay;
            case SECONDS:
                return TimeUnit.MILLISECONDS.toSeconds(delay);
            case MINUTES:
                return TimeUnit.MILLISECONDS.toMinutes(delay);
            case HOURS:
                return TimeUnit.MILLISECONDS.toHours(delay);
            case DAYS:
                return TimeUnit.MILLISECONDS.toDays(delay);
            case MICROSECONDS:
                return TimeUnit.MILLISECONDS.toMicros(delay);
            case NANOSECONDS:
                return TimeUnit.MILLISECONDS.toNanos(delay);
            default:
                break;
        }
        return delay;
    }

    @Override
    public int compareTo(Delayed o) {
        long delay1 = this.getDelay(TimeUnit.MILLISECONDS);
        long delay2 = o.getDelay(TimeUnit.MILLISECONDS);
        int result = Long.valueOf(delay1).compareTo(Long.valueOf(delay2));
        if (result != 0) {
            return result;
        }
        // 时间判断无法区分时，执行如下判断(用于维持 compareTo 的使用约束)
        if (this.equals(o)) {
            return 0;
        } else {
            return this.hashCode() - o.hashCode();
        }
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((content == null) ? 0 : content.hashCode());
        return result;
    }

    @SuppressWarnings("rawtypes")
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        DelayedElement other = (DelayedElement) obj;
        if (content == null) {
            if (other.content != null)
                return false;
        } else if (!content.equals(other.content))
            return false;
        return true;
    }
}